New quaternary compounds of pyridine



limited States Patent NEW QUATERNARY COMPOUNDS 0F PYRIDINE ALDEHYDE ACETALS Adolf Christian Josef Opfermann, Bergisch-Gladbach, Germany No Drawing. Application February 18, 1957 Serial No. 640,623

Claims priority, application Germany February 23, 1956 2 Claims. (Cl. 260-297) This invention relates to new quaternary compounds of pyridine aldehyde acetals and to a process for the production thereof.

These new compounds are pyridinium compounds of the following general formula i. wherein the pyridine nucleus may be further substituted, R and R are the residues of an alcohol, X is a radical of the group consisting of alkyl-, alkenyl-, aralkyland aryl-radicals and X is the anion of an acid. Advantageously, R and R are the residues of an aliphatic alcohol containing l4 carbon atoms in the molecule, X is a radical of the group consisting of the alkyland alkenylradicals containing 1-4 carbon atoms in the molecule and X is a halogen atom, preferably an iodine atom.

It has been found that these new quaternary compounds of pyridine aldehyde acetals have valuable therapeutic properties in that they promote the blood circulation in the skin and especially the curing of rheumatic diseases. These compounds are preferably applied as dilute alcoholic solutions to the skin. The proportion of the quaternary compounds of pyridine aldehyde acetals in these solutions can for example be 0.01 to preferably 0.1 to 1%. When these compounds are used in substantially higher concentrations, the circulation efiect is often too high and frequent use of the compounds can lead to undesirable secondary phenomena, such as for example causing the skin to become too brittle. Lower aliphatic alcohols such as isopropyl alcohol can for example be used as solvent. Moreover, the products according to the invention can be used with good results as active substances in cosmetic preparations, for example in hair creams or skin oils. The stimulation of the skin caused by the products of the invention is clearly visible. The skin acquires a live, fresh and healthy tone; its breathing is improved and the clogging of the pores which otherwise readily occurs With cosmetic preparations is avoided or apparently reduced. When the gums are treated with preparations according to the invention, the gum is given a red healthy tone. The novel compounds can be produced either by quaternizing a pyridine aldehyde acetal or by converting a quaternary pyridine aldehyde into an acetal. The quaternisation can be carried out in accordance with the invention by mixing 1 mol of a pyridine acetal with about 1 mol of a quaternising component, preferably an alkyl or an alkenyl halide containing 1-4 carbon atoms in the molecule, heating the reaction mixture for several hours to a temperature of about 45-100 C. and isolating the reaction product.

The pyridine aldehydes can be unsubstituted or they may be substituted by alkyl, aralkyl, aryl, carboxylic acid, carboxylic acid ester groups or halogen atoms. It

is also possible to use dialdehydes such as pyridine-2,6- dialdehyde as initial material. It is preferred to use unsubstituted pyridine aldehydes, or pyridine aldehydes which are substituted by lower alkyl radicals, containing for example 1-4 carbon atoms, or by halogen atoms.

Alcohols of the aliphatic, araliphatic and vheterocyclic series can be used as acetalisation components. It is preferred to use lower aliphatic alcohols with l-4 carbon atoms. Cyclo-aliphatic alcohols, for example thenthol or terpineol, or heterocyclic alcohols such as'fur furyl alcohol can however also be employed. The ace tals can for example be produced by the processes of German patent specification No. 871,444 or 907,292.

Alkyl, alkenyl and aralkyl halides, aryl halides having a displaceable halogen atom, dialkyl sulphates, alkyl or aryl sulphonic acid esters such as p-toluene sulphonic acid alkyl esters and .acid halides can for example be used as quaternising components. The alkyl chains can be short or long without this having important influence on the effect of the final products. The preferred compounds for use as quaternising components are alkyl or alkenyl compounds with l-4 carbon atoms in the alkyl or alkenyl chain and benzyl or p-halogen benzyl halides. The halides of carboxylic acids and sulphonic acids ca ,be used as acid halides.

The following examples further illustrate the. invention: Example 1 26.7 g. of methyl iodide are slowly added dropwise to 28.8 g. of pyridine-3-aldehyde dimethyl acetal. The temperature should not rise above 70 C. while the methyl iodide is being added, After the addition of methyl iodide is complete, the reaction product is kept for 1 hour at a constant temperature of 70 C. N-methylpyridinium-B-aldehyde dimethyl acetal iodide crystallises out during cooling. The methyl iodide, and its acetal which have not reacted during the conversion are removed by washing with ether. The crystals which remain have a constant melting point of 105 C. The yield is more than of the theoretical. v

Erample 2 Example 3 I 15.3 g. of pyridine-B-aldehyde dimethyl acetal and 60 g. of 2,4-dinitro-l-chlorobenzene are heated for 1 hour at C. The reaction mixture is dissolved in 100 cc. of absolute methanol and the solution is filtered. After approximately 3 hours, the excess 2,4-dinitro-1-chloro benzene crystallises out. The crystals are filtered off with suction and the filtrate is concentrated by evaporation in vacuo until it has the thickness of syrup. The syrup is dissolved in acetone and the solution is mixed with ether. N-(2,4-dinitrophenyl)-pyridinium-3-aldehyde dimethyl acetal chloride crystallises out. The crystals are dried on clay and have a melting point of C. The yield is 90% of the theoretical. 1

Example 4 is being used; After the addition of methyl iodide is complete, the reaction product is kept for 1 hours at 70 C. N-methyl-pyridinium-4-aldehyde-dimethyl acetal iodide crystallises out during cooling. The methyl. iodide and acetal which have-not enteredintoreaction areremoved by washing with ether; The crystals which remain have a meltingpoint of 95 C. The yield is 95% of the theoretical.

Example 5 15.0 g. of methyl iodide are slowly added dropwise-to 22.7 g. of 2,6-pyridine dialdehyde tetramethyl acetal. The temperature should not rise above 50 C. while the methyl iodide. is being added. After the methyl iodide has been added, the temperature is kept constant at' 50 C. for one hour. N-methyl-pyridinium-dialdehyde tetramethyl'acetal iodide crystallises out after cooling. The methyl iodide and the acetal which have not entered into reaction are removed by washing with ether. The yield is 95% of the theoretical.

Example 6 15.6 g. of ethyl iodide are slowly added dropwise to 15.3 g. of pyridine-3-aldehyde dimethyl acetal. Care is taken that the temperature does not rise above 50 C., while the ethyl iodide is being added. When the addition of ethyl iodide is complete, the reaction mixture is kept at a constant temperature of 50 C. for 5 hours. A viscous reaction product is formed, which is mixed with acetone and thoroughly shaken. The N-methylpyridinium-3-aldehyde dimethyl acetal iodide which is formed then separates out as crystals. These are washed with acetone and dried in a desiccator in vacuo over calcium chloride. The crystals have a melting point of 130 C. The yield is 95% of the theoretical.

Example 8 10.9 g. of ethyl bromide are slowly added dropwise to 15.3 g. of pyridine-3-aldehyde dimethyl acetal. The temperature of the reaction mixture should not rise above 50 C., while the ethyl bromide is being added. After the addition of the ethyl bromide is complete, the reaction mixture is kept at a constant temperature of 50 C. for 5 hours. After about 12 hours,.crystals of N-ethylpyridinium-B-aldehyde dimethyl acetal bromide separate out. The crystals are filtered off, washed with acetone and dried in a desiccator in vacuo over calcium chloride. The crystals have a melting point of 169 C.' The yield is about 90% of the theoretical.

Example 9 22.2 g. of N-propyl iodide are slowly added dropwise to 20.0 g. of pyridine-3-aldehyde dimethyl acetal. After the N-propyl iodide has been added, the reaction mixture is kept-at a constant temperature of 100 C.'for 5 hours. N-propyl-pyridinium-3-aldehyde dimethyl acetal iodide crystallises out during cooling. The crystals are Washed with acetone and dried in a desiccator in vacuo over calcium chloride. They have a melting point of 128 C. The yield is 95% of the theoretical.

Example 10 7.1 g. of methyl iodide'are slowly added' dropwise. to 200g: of pyridine-3-aldehyde dimenthyl acetal. The mixture-is: heated m 100" C., and the temperature is kept constant for 3 hours. A viscous reaction mixture is formed, which is mixed with acetone and thoroughly shaken. Crystals of the N-methyl-pyridinium-S-aldehyde dimenthyl acetal iodide which is formed then separate out. These are dried on clay in a desiccator in vacuo over calcium chloride. The crystals have a melting point of 165 C. I

Example 11 10 g. of pyridine-3-aldehyde dimethyl acetal and 14.25 g. of benzyl iodide are thorough mixed with one another. The temperature, which slowly rises, is kept constant at 70 C. for 1 hour. During the cooling, a viscous reaction product is formed, which is mixed with acetone and thoroughly shaken. By cooling the resulting mixture in a mixture of ice and sodium chloride, the crystals of the N-benzyl-pyridinium-3-aldehyde dimethyl acetal iodide which is formed are then caused to crystallise out. The crystals immediately start to liquefy in air. The yield is of the theoretical.

Example 12 There are indicated below a number of possible formulations of cosmetic preparations containing the products according to the invention:

(a) Hair cream:

24 g. of stearin 6 g. of glycerine 28 B. l g. of potassium hydroxide 0.1 g. of sodium-hydroxide 2 g. of butyl stearate 66.9 g. ofwater 0.1 g. of pyridine-4-aldehyde dimenthyl acetal are combined and stirred until'an emulsion is formedl (b) Skin oils:

65 g.:of castor oil and 35 g. of ethanol are mixed with 0.4 g. of pyridine-3 aldehyde dibenzyl acetal and perfumed as required.

(0) Dentifrice:

1000 g. of glycerine 400 g. of water 110 g. of silica gel 1.3 g. of 6-methyl-pyridine-Z-aldehyde diethyl acetal and 25 cc. of peppermint oil are kneaded together. The jelly which is obtained has added thereto:

are thoroughly mixed and used as a gargle.

What I claim is:

l. N methyl-pyridinium-Il-aldehyde dimethylacetaliodide.

2. N-methyl-pyridinium-4-aldehyde dimethyl acetaliodide.

Refereuces Cited in the file of'this patent UNIT ED STATES PATENTS Anderson Feb: 19, 1957 OTHER REFERENCES Harries et-al.: LiebigTs'Ann, .vol; 410, page. (1915 

1. N-METHYL-PYRIDINIUM-3-ALDEHYDE - DIMETHYL - ACETALIODIDE.
 2. N-METHYL-PYRIDINIUM-4-ALDEHYDE -DIMETHYL -ACETALIODIDE. 